Octal to Binary Converter

Octal is the base-8 number system, using digits 0–7. Because each octal digit maps exactly to 3 binary bits, it was historically popular for compactly displaying binary data on systems with word sizes divisible by 3. Today its main practical use is Unix/Linux file permissions, expressed as three-digit octal numbers like 755.

Binary is the base-2 number system used natively by computers: every value is stored as a sequence of bits, each either 0 or 1. Digital logic gates, boolean operations, and low-level memory all operate directly in binary — it's the only number system a CPU actually understands.

To convert octal to binary, expand each octal digit into exactly 3 binary bits and concatenate them. For example, octal 312 becomes 011 001 010, or 11001010 once the leading zero is dropped.